My whole flock all of the sudden turned on my favorite hen!?! Why?

Well, this happened awhile back, but we got two new birds from my friend. We got a Buff Orpington, and a mixed breed. Licorice, the mixed breed was protecting Red, our Buff. But, then Red stopped getting beaten up, but then Red turned on Licorice and so did the rest of the flock. We immediately took her out. A few days later we tried again, but it went even worse, she got the skin on her head ripped off( not the comb). Later on we got some chicks, so when they got their feathers we put them in with Licorice. She instantly became attached, so we split up our coop and put our 5 little chicks and Licorice in one part, then put the other birds in the other part. But our rooster, Doc, pushed open the gate and got in with the chicks and Licorice. So, we just nailed the door to the wall so he couldn't get it open. Well, about 2 months later my mom said the chicks have to live with the rest of the flock now. So we built Licorice her own special little coop in my Grandpas garage ( my grandparents live right beside us). About a week later my mom asked if she could try Licorice with the rest of the flock again, I immediately told her NO! But she didn't listen, she put her in anyways. Licorice got her eye peck out by of all our flock, Red! I couldn't Belive it, first my mom didn't listen, then, Red, Licorice's once closets friend, pecked her eye out! So we put her back ever science. I don't know what to do! We didn't treat her eye, my mom said she wasn't going to do it. She had her eye pecked out about five months ago, it just has some cream colored puss coming out of it. Please help! I would like to know if someone can help me figure out why the whole flock turned on her so quickly, and also if there is anything that we need to do for her eye.